1. Field of the Disclosure
This disclosure generally relates to self-aligning tools with mandrels and methods of using the same for installing and positioning expandable members, such as expandable bushings.
2. Description of the Related Art
Conventional installation tools are used to install bushings in openings within workpieces. These installation tools often have an expansion mandrel sized to fit within an opening of the bushing. Expansion mandrels are often formed of a hard metal, such as tool steel. After the bushing is slid over the expansion mandrel, the bushing and mandrel are simultaneously inserted into the opening of the workpiece. Unfortunately, an installer may have to manually hold the bushing at a desired position along the mandrel because the bushing may otherwise slide along the mandrel. This may cause complications during the installation process and increase the installation time.
After the bushing and corresponding mandrel are placed in the opening, the mandrel is pushed or pulled through the opening of the bushing to expand the bushing. The bushing is expanded until an interference fit is formed between the bushing and workpiece. During the expansion process, the installation tool must be adequately aligned with the opening in the workpiece in order to reduce side loads applied to the mandrel. For example, if a longitudinally-extending axis of the mandrel is misaligned with a longitudinally-extending axis of the opening, undesirable side loads may be applied to the mandrel. These side loads may cause excessive wear, high localized stresses (e.g., stresses in the workpiece, expandable member, mandrel, etc.), and improper positioning of the bushing. The excess wear can result in frequent part replacement. The high stresses can lead to part failure, such as breaking of the mandrel and/or damage to the workpiece, which can cause manufacturing delays. Thus, side loads can undesirably increase the costs for replacing and maintaining tools, frequency and length of manufacturing delays, and reduce the quality of the installed bushings.
Bushings are often installed in longitudinally-extending holes positioned along angled surfaces of workpieces. That is, the longitudinal axes of the holes are not orthogonal to the surfaces of the workpieces. An installation tool having an angled nose cap may be used to install bushings in these types of holes. The angled nose cap is a unitary structure fixedly coupled to a pull gun. A front face of the nose cap is angled so as to align the mandrel with the longitudinally-extending axis of the hole in the workpiece.
When the angled surface of the nose cap is placed against the surface of the workpiece adjacent the opening, the mandrel can pass through the nose cap and the bushing located in the workpiece. Unfortunately, the user has to select an appropriately angled nose cap for aligning the mandrel with the hole. A single angled nose cap is only suitable for use with a rather narrow range of angles. To select an appropriate angled nose cap, an installer measures the angle defined by the longitudinally-extending axis of the hole in the workpiece and the working surface of the workpiece. An angled nose cap is then selected corresponding to the measured angle. The angled nose caps are often indexed for various surface angles.
Many indexing tools require a minimum surface size for properly taking angle measurements. Unfortunately, the surface angle of the workpiece may be difficult to measure because the area of the surface surrounding the through-hole in the workpiece may be relatively small. Indexing tools may also be unable to measure adequately the curvature of the workpiece's curved surfaces. Additionally, it may be difficult to find any suitable “square” features or edges of the workpiece which are used for orienting the handpiece and associated mandrel. Thus, proper installation of expandable members may be difficult and require complicated measuring equipment.
Additionally, in order to install bushings at different locations, a user may be required to select and use different angled nose caps for use with a single installation tool. Because the installer has to remove and couple various angled nose caps, the installation time can be undesirably long.
In an alternative method, a spacer is used to align a mandrel of an installation tool with a hole in a workpiece. The spacer provides a surface that is perpendicular to a longitudinal axis of the hole. Similar to the angled nose caps, the angle of the workpiece's surface has to be determined before selecting an appropriately sized spacer. Additionally, multiple spacers are often needed for properly installing bushings at different locations.
Consequently, conventional installation tools may not adequately meet certain quality and installation needs.